Conventionally, a tire curing mold, which is one example of molds, includes side molds for enclosing both side regions of an uncured tire, which is an object to be heated, and a plurality of crown molds for enclosing the crown region of the uncured tire. The tire curing mold performs the heating and curing of the uncured tire by transferring heat supplied from the outside to the uncured tire. Also, the amount of heat given to the uncured tire from each of the molds depends on the heat transfer rate of the metal, which is the material used for the molds. Thus, the amount of heat given to the uncured tire is nearly the same irrespective of the different regions of the tire.
FIG. 12A is a graph showing temporal changes in the degree of curing in the vicinity of center area and the vicinity of shoulder areas of the crown region of the tire cured with the tire curing mold capable of giving a uniform amount of heat to different regions of the uncured tire. As shown in the figure, due to the difference in gauge thickness, the degree of curing (vulcanization) in the vicinity of center area with a thinner gauge thickness rises faster than in the vicinity of shoulder areas with a thicker gauge thickness. At the point when the degree of curing in the vicinity of shoulder areas with the thicker gauge thickness reaches a proper level, the degree of curing in the vicinity of center area tends to exceed the proper level and thus render an overcuring there. Therefore, it is difficult to achieve an optimum degree of curing in both the vicinity of center area and the vicinity of shoulder areas at the same time.